This invention relates generally to the construction of retaining walls used in landscaping applications where such walls are used to provide lateral support between differing ground levels. More particularly, the present invention relates to a retaining wall that uses a series of differently sized, pre-formed horizontal and vertical blocks that operatively connect with each other along adjacent courses to resist pressure exerted against the wall by retained back-fill material and ground water.
Retaining walls are widely used in a variety of landscaping applications. Typically, they are used to maximize or create level areas and also to reduce erosion and slumping. They may also be used in a purely decorative manner. In the past, retaining wall construction was labor intensive and often required the skills of trained tradespeople such as masons and carpenters. More recently, retaining wall construction has become significantly simplified with the introduction of self-aligning, modular, molded blocks of concrete that may be stacked in courses without the use of mortar or extensive training. With these types of blocks, it is possible to erect a retaining wall quickly and economically, and the finished product creates the impression and appearance of a conventional block and mortar retaining wall. The feature that allows such blocks to be so easily and precisely assembled is the interconnection between adjacent courses of blocks. Typically, each block will include a projection and a recess located at oppositely facing surfaces, such as a top surface and a bottom surface, for example. The projection and recess are complimentarily shaped, with the projection protruding beyond the bottom surface of the block and with the recess extending inwardly from the top surface of the block. In use, a projection of a first block is received within the recess of a second block to interconnect and position the blocks adjacent each other in a predetermined relation. With a plurality of blocks, such interconnections make it possible to lay courses of blocks in an accurate and expedient manner. Moreover, such an assembled retaining wall is able to resist lateral forces exerted by the material being retained and reduce bowing. Blocks having these interconnections are usually the same size and may be assembled in a coplanar arrangement in only a simple, running bond pattern. In a variation of the aforementioned blocks, the projection and recess may be arranged so that adjacent courses are offset a predetermined amount. With this type of block, each successive course may be offset from the preceding course by the same amount so that the assembled wall is skewed at a predetermined angle from the vertical. These blocks also have the same dimensions to enable them to set in only a simple, running bond pattern.
A recent development in mortarless retaining walls has been the advent of blended pattern retaining walls. These walls differ from the aforementioned walls in that the preformed blocks used to construct a retaining wall are differently sized. This feature allows retaining walls to be assembled in a variety of patterns and bonds. Usually, these types of preformed blocks are horizontally and vertically oriented and have dimensions that are based upon an incremental unit such as the thickness of a horizontal, preformed block. For example, the thickness of a horizontal block is one increment and the height of a vertical block is two increments. With these types of preformed blocks, it is possible to construct a retaining wall with no discernable courses. A drawback with such a retaining wall is that setbacks are not possible and the assembled retaining wall must be substantially vertical. Alternatively, a retaining wall may be arranged in thick courses, and the blocks within these thick courses may be randomly arranged. For example, a course may be two incremental units high within which the differently dimensioned preformed blocks are arranged. Or, the course may be three incremental units high within which the differently dimensioned preformed blocks are arranged. There are several drawbacks with this type of wall. One drawback is that the vertical blocks dictate the height of the course. Thus, if vertical blocks are used, each entire course must be coplanar and all of the blocks must lie in the same plane. Otherwise, the projections of blocks in one course would not be able to be received within the recesses in blocks of another course, and the interconnection would be defeated. Another drawback with such this type of wall is that the number of arrangements available within each course is limited, and a truly random arrangement is not possible.
The present invention comprises a plurality of horizontally elongated and vertically elongated, preformed blocks that may be assembled to form a retaining wall. Each horizontal preformed block includes a front member and a rear member connected to each other by a web, opposing sides, a top portion and a bottom portion. The horizontal blocks may be formed in a series of predetermined incremental thicknesses whose additive thickness is equal to the height of the vertical block. For example, the horizontal blocks may have incremental thicknesses of one, two and three units, while the vertical preformed block is three units tall. Thus, the horizontal blocks may be stacked in whatever units which, when added together, would be three units tall.
The front member of each horizontal block includes a rearwardly facing portion having stop surfaces that are aligned with each other and are used to operatively connect adjacent courses of blocks. Each horizontal block also includes a recess and a projection located at oppositely facing support surfaces, respectively. Preferably, the recess is located at the top of each block and extends downwardly with respect to the top support surface of each block forming a through slot with open ends in spaced relation to the front member of each block. An important feature of the recess in these blocks is that the recess includes a stop surface that is in alignment with stop surfaces of the rearwardly facing portion of the front member of each block. Together, these stop surfaces form a single stop surface that extends substantially along the length of each horizontal block. This greatly increases the utility of each block because it allows the blocks of an adjacent upper course of blocks to be slidingly positioned with respect to a lower course of blocks as the retaining wall is being constructed. This adds to the number of possible arrangements of blocks and helps one construct a stronger retaining wall because aligned vertical joints between adjacent courses may be easily avoided.
The projection on the horizontal block extends downwardly with respect to the bottom surface of each block. Preferably, the width of the projection is substantially equal to the width of web that connects the front and rear members together. Each projection includes an indexing surface that is configured to operatively contact a stop surface of an adjacent course of blocks.
Each vertical preformed block includes a front member and a rear member connected to each other by upper and lower webs, opposing sides, a top portion and a bottom portion. The front member of each vertical block includes a rearwardly facing portion having a stop surface. Each vertical block also includes a recess and a projection located at oppositely facing support surfaces, respectively. Preferably, the recess is located at the top of each block and extends downwardly with respect to the top support surface of each vertical block forming a through slot with open ends in spaced relation to the front member of each block. The recess in these blocks includes a stop surface that is coincident with the stop surface of the front member, and, as with the horizontal blocks, the stop surface extends substantially along the width of each vertical block.
As with the horizontal block, the projection on the vertical block extends downwardly with respect to the bottom surface of each block, and preferably its width is coincident with the width of the vertical block. Each projection of the vertical block also includes an indexing surface that is configured to operatively contact the stop surface of an adjacent course of blocks.
Another important feature of the aforementioned blocks relates to the operative connections that occur between the projections and recesses of adjacent courses of blocks. This is achieved by using blocks that have a stop surface which is fixed relative to a common feature of the blocks, such as the viewable surface, and blocks which have indexing surfaces located at a series of predetermined distances from a common feature of the blocks, also such as the viewable surface. For example, to construct a coplanar wall, one would select those blocks where the indexing surfaces are at a first predetermined position. Alternatively, to construct a wall that tilts at a slight angle with respect to the vertical, a different set of blocks with indexing surfaces located at a second predetermined position would be used. And, to construct a wall which tilts at a greater angle with respect to the vertical, yet another set of blocks with indexing surfaces located at a third predetermined position would be used, and-so-on. This feature may be combined with the other features discussed above to produce a myriad of retaining wall configurations that may include combinations with different setbacks and/or no setbacks.
An object of the present invention is to provide a retaining wall that may be assembled without the use of mortar.
Another object of the present invention is to increase the number of arrangements possible between adjacent blocks in a retaining wall.
Yet another object of the present invention is to reduce undesired lateral movement between adjacent courses in a retaining wall.
A feature of the present invention is that vertical, preformed blocks have a height that is equivalent to two or more stacked horizontal preformed blocks.
Another feature of the present invention is that the horizontal, preformed blocks may have the same thickness or may have complimentary thickness whose additive thickness is equal to the height of vertical, preformed blocks.
Another feature of the present invention is that the courses of blocks may be assembled in a coplanar or one of several predetermined offset relations.
An advantage of the present invention is that the use of differently sized and oriented preformed blocks permits a retaining wall to be configured into a myriad of configurations.
Another advantage of the present invention is that each course presents a substantially contiguous, aligned stop surface against which indexing surfaces of projections of an adjacent course of blocks are positioned.
Additional objects, advantages and features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combination particularly pointed out in the appended claims.